(i) Field of the Invention
This invention relates to novel water-soluble lubricant compositions for use in metal working, and more particularly, to metal working water-soluble lubricant compositions useful as lubricants in metal working such as plastic working, machining and grinding, which comprise salts or quaternary ammonium salts of water-soluble cationic or amphoteric polymer compounds.
(ii) Description of the Prior Art
General and hitherto employed liquid lubricants in metal working such as plastic working, machining and grinding are formed into emulsions with predetermined concentrations of emulsifiers such as surfactants, and supplied to the surfaces of metal materials to be worked. Such liquid lubricants have a characteristic that they owe the lubricating performance to particles of liquid lubricants emulsified with surfactants etc., which is deposited on the surfaces of metal materials to be worked. Especially, liquid lubricants emulsified in water are advantageous in view of cooling effect on heat generated when metal materials are worked, and also from the economical standpoint of circulation-use of emulsions. On the other hand, they have the following drawbacks in dealing with the emulsions;
(1) Poor stability of emulsions,
(2) Contamination of emulsions with contaminants such as metal powders and scums produced when metal materials are worked,
(3) Contamination of the surfaces of metal materials to be worked with the above contaminants,
(4) Reduced load resistance which is alternately introduced when the amount of lubricant particles on the surfaces of material to be worked is made reduced to obtain an enhanced stability of emulsion,
(5) Waste water treatment of emulsions is difficult, and
(6) Corrosion and rusting of materials to be worked caused mainly by water.
Accordingly, development of such water-soluble lubricants as to overcome the above drawbacks is strongly desired. In this connection, however, lubricants utilizing emulsifiers have as yet a number of difficulties to be solved and are not satisfactory.